This invention relates to a manufacturing method of a semiconductor device, and in particular to a manufacturing method of a semiconductor device having a structure, in which lower electrodes of crown-shaped capacitors are supported by a plurality of support films.
In a related-art semiconductor device manufacturing method, plural insulator beams are formed sequentially from the lower layer side. This type of technique is disclosed for example in Japanese Laid-Open Patent Publication No. 2003-142605.
More specifically, a first insulating beam film is formed on a first sacrificial insulating film and then the first insulating beam film is selectively etched to form a first insulator beam having a desired pattern. Subsequently, a second sacrificial insulating film and a second insulating beam film are sequentially formed on the first insulator beam and the exposed first sacrificial insulating film. In the same manner as for the first insulating beam film, the second insulating beam film is selectively etched to form a second insulator beam having a desired pattern.
Subsequently, through holes are formed to pass through the second insulator beam, the second sacrificial insulating film, the first insulator beam and the first sacrificial insulating film, and a conductive film functioning as lower electrodes of capacitors is formed so as to cover the inner surfaces of the through holes. The conductive film thus formed is connected to the second insulator beam and first insulator beam exposed in the through holes.
After that, the lower electrodes can be supported by the second insulator beam and first insulator beam even if the second sacrificial insulating film and the first sacrificial insulating film are removed. Thus, the lower electrodes can be prevented from collapsing, and crown-shaped capacitors having a higher aspect ratio can be formed.